JPH0797587A - Refrigerator oil composition for hfc - Google Patents

Abstract

PURPOSE:To improve the durability and reliability in the system in which HFC refrigerant is used without causing troubles in the componential parts. CONSTITUTION:In the oil composition for refrigerators which is used by the coexistence of hydrofluorocarbon refrigerant, the oil composition is composed of fluorine-containing oil, hydrocarbon oil and a synthetic oil having some polar groups.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating machine oil composition, and more particularly to a refrigerating machine oil composition using a hydrofluorocarbon (hereinafter abbreviated as HFC) type refrigerant, a hermetic compressor and a refrigerating apparatus using the same. Regarding

[0002]

2. Description of the Related Art There is an urgent need to develop a refrigeration system using an HFC-based refrigerant that does not destroy the ozone layer, while restricting the use of CFCs that lead to the destruction of the ozone layer.

The refrigeration system has four functions of evaporation, compression, condensation and expansion.
It is represented by an air conditioner, a refrigerator, etc., in which a refrigeration cycle consisting of three functions is incorporated. In the refrigeration cycle, the refrigerant circulates while repeatedly changing from liquid to gas and from gas to liquid. Further, a refrigerating machine oil composition is enclosed in the refrigerant compressor in order to facilitate lubrication of the compression mechanism.

Taking a refrigerator as an example, a refrigerating cycle will be described with reference to FIG. The refrigerant is compressed by the compressor 23, which is a compression mechanism, cooled through the pedestal pipe 24, which is a condensation mechanism, the heat radiation pipe 25, and the clean pipe 26, expanded through the capillary tube 21, which is an expansion mechanism, and is an evaporation mechanism. It evaporates in the evaporator 22 and cools the inside of the refrigerator 27. Then, it is compressed again by the compressor 23.

Conventionally, dichlorodifluoroethane (hereinafter referred to as CFC12) or monochlorodifluoromethane (hereinafter referred to as HCFC22) has been used as a refrigerant for such a closed refrigeration cycle.
Is mainly used and circulates in the refrigeration cycle. Further, as the refrigerating machine oil that is enclosed to maintain the lubricity of the compressor 23, naphthene-based or paraffin-based mineral oil that is soluble in CFC12 and HCFC22 is used. However, recently the above refrigerants (CFC12, HCFC22)
Since it has become clear that the release of CFCs from the ozone gas will lead to the destruction of the ozone layer and seriously affect the human body and biological systems,
CFC12 with high ozone depletion potential ODP value (ODP value: 1.0
) Or an ODP value of 0 or more HCFC22 (ODP value: 0.0
The usage of 5) etc. is gradually reduced, and it is decided not to use it in the future.

Under these circumstances, 1,1,1,2-tetrafluoroethane (hereinafter referred to as HFC) as a CFC having an ODP value of 0 and no chlorine is used as an alternative refrigerant of HCFC22.
134a), 1,1-difluoroethane (hereinafter HFC15
2a), difluoromethane (henceforth HFC32), pentafluoroethane (henceforth HFC125), 1,1,1-trifluoroethane (henceforth HFC143a), etc. have been developed. Further, in the case where sufficient freezing characteristics cannot be obtained with these refrigerants alone, a mixed refrigerant in which the above refrigerants are combined has been developed even in the case where an azeotropic mixture is not obtained. For example, HFC32 / HFC12
5 (weight ratio 60/40), HFC32 / HFC134a (weight ratio 25 ~
30/70 to 75), HFC134a / HFC125 (weight ratio 55/45), etc., and HFC32 / HFC134a / HFC125 (weight ratio 30
/ 60/10), HFC125 / HFC143a / HFC134a (weight ratio 44
/ 52/4) and other three-mix HFC refrigerants have been developed. Since each HFC which constitutes these mixed refrigerants also behaves differently with respect to each refrigerating machine oil, development of a refrigerating machine oil particularly suitable for these mixed refrigerants is desired.

A refrigerant compressor in which refrigerating machine oil is enclosed will be described with reference to FIG. FIG. 2 shows an example in which the hermetic rotary compressor is cut away. Stator 2 in a closed casing 1
A motor mechanism 4 including the rotor 3 and the rotor 3 is installed. A compression mechanism 5 is provided below the motor mechanism 4, and the compression mechanism 5 is driven by the motor mechanism 4 via the shaft 8. The refrigerant introduced from the supply pipe 6 via the accumulator (not shown) is compressed by the compression mechanism 5 and is once discharged into the casing 1. Then, the refrigerant is discharged from the discharge pipe 7 provided in the upper portion of the casing 1 to the refrigerator side. To supply. Refrigerating machine oil 20 is contained to lubricate the compression mechanism 5. In FIG. 2, 9 is a bearing, 10 is a cylinder, 11 is a sub-bearing, 12 is a crank, and 13 is a bearing.
Is a roller, 14 is a blade, and 15 is a spring.
Other examples of the refrigerant compressor include a hermetic reciprocating refrigerant compressor in which a compression mechanism is composed of a piston and a reciprocating cylinder.

As the characteristics required for the refrigerating machine oil used in such a refrigerant compressor, the refrigerating machine oil must have compatibility with the refrigerant in order to improve the oil return in the cycle, and the sliding members of the compression mechanism section It is necessary to have appropriate lubricity for smooth operation, to prevent rust and corrosion from occurring in each sliding member of the compression mechanism, and to prevent deterioration of the insulating property of the organic insulating material component.

[0009]

However, the reality is that no HFC refrigerating machine oil composition satisfying the above-mentioned required characteristics has been developed. For example, polyester-based oils, polyether-based oils, polycarbonate-based oils, fluorine-based oils, etc. are known as refrigerating machine oils that dissolve in HFC134a, which is almost insoluble in conventional refrigerating machine oil, but mixed HFC-based refrigerants. Refrigerating machine oil has the following problems.

Table 1 shows the results of examining the compatibility between each of the above refrigerating machine oils and the HFC refrigerant.

[Table 1] From Table 1, there is no single oil that has common compatibility with each refrigerant alone, that is, polyester-based oils, polyether-based oils, and polycarbonate-based oils have poor compatibility with HFC143a at around 0 ° C. Fluorine-based oils have poor compatibility with HFC32. Therefore, one type of refrigerating machine oil has a problem that there is no refrigerating machine oil having good compatibility with the mixed refrigerant containing HFC32 or HFC143a.

Since polyester type oils, polyether type oils and polycarbonate type oils have high hygroscopicity, rust and corrosion will occur in the metal material inside the compressor when used for a long period of time, and the electrical insulation of the organic material will be insufficient. There is a problem of causing a decrease. In addition to this, in the case of a refrigerating machine oil having an ester group in the molecule as an effect of water, there is a problem that the oil itself or an organic material is hydrolyzed, resulting in a significant deterioration in quality and being unusable for a long period of use.

Further, from the viewpoint of lubricity, the conventional mineral oil type refrigerating machine oil contains a cyclic compound, and the oil film forming ability was relatively high. It is a chain compound that does not contain, and cannot maintain an appropriate oil film thickness under severe sliding conditions.
Also, in the CFC or HCFC refrigerants that have been conventionally used, Cl atoms in the molecule react with Fe atoms of the metal base material in the compression mechanism to form an iron chloride film, and this iron chloride film acts as a self-lubricating film. And contributed to the improvement of wear resistance. On the other hand, the HFC-based refrigerant is disadvantageous in lubricity because it does not form a self-lubricating film such as iron chloride because Cl atoms do not exist in the molecule. Therefore, there is a problem that the lack of lubricity must be improved by changing the material or design of the sliding portion.

When an HFC-based refrigerant and the above-mentioned polyester-based oil are used in a refrigerating apparatus, a refrigerant compressor or a refrigeration cycle is used in an expansion mechanism section such as a capillary tube which is a low temperature and refrigerant rich section of the refrigeration cycle section. There is a problem that a substance that remains as a cleaning residue is deposited during the manufacturing process.

As described above, when using an HFC type refrigerant which is a refrigerant which substitutes for CFC12 or HCFC22, the compatibility,
When a single refrigerating machine oil such as the above-mentioned polyester oil is used from the viewpoint of hygroscopicity, lubricity, etc., there has been a problem that defects occur in the constituent parts and the quality and durability are greatly reduced.

The present invention has been made in consideration of such conventional circumstances, and particularly in a system using a mixed HFC refrigerant as a refrigerant, does not cause any trouble in the components.
An object of the present invention is to provide a refrigerating machine oil composition capable of improving durability and reliability.

[0016]

The refrigerating machine oil composition of the present invention used together with an HFC-based refrigerant is composed of a fluorine-based oil, a hydrocarbon-based oil and a synthetic oil having a polar group. It is characterized by

The HFC type refrigerant according to the present invention is carbon,
A compound consisting of fluorine and hydrogen, which is a conventional refrigerant
It is an alternative to CFC12 and HCFC22. For example HFC
Examples are 134a, HFC152a, HFC32, HFC125, and HFC143a. These HFCs can be used alone or as a mixture of two or more kinds. For example, 2
HFC32 / HFC125 as seed mixture (weight ratio 60/40), H
FC32 / HFC134a (weight ratio 25-30 / 70-75), HFC134a
/ HFC125 (weight ratio 55/45), etc.
FC32 / HFC134a / HFC125 (weight ratio 30/60/10), HFC
Examples include 125 / HFC143a / HFC134a (weight ratio 44/52/4) and the like.

The fluorinated oil according to the present invention is a compound consisting of carbon, fluorine and oxygen, and has at least one in its molecule.
Refers to a compound which has a chemical structure - -CF ₂ -O- CF _2. More specifically, it refers to a compound represented by the following formula.

[Chemical 1] Here, n refers to an integer of 10 to 60.

The hydrocarbon-based oil according to the present invention is a compound composed of carbon and hydrogen, and is a naphthene capable of dissolving a hydrocarbon-based wax which is likely to remain as a cleaning residue in a refrigerant compressor or a refrigeration cycle manufacturing process. Particularly preferred are mineral oils, paraffinic mineral oils and synthetic alkylbenzene oils.
Any of these hydrocarbon-based oils can be used as long as they are liquid in the temperature range of -40 to 120 ° C. Specific examples of naphthene-based mineral oil include Suniso 3G, Suniso 4G, etc. (manufactured by Sun Oil Co., Ltd.), and paraffinic mineral oil is exemplified by Freol S15 and Freol S.
32, Freol S56, etc. (manufactured by Nikko Kyokushi Co., Ltd., trade name), and examples of the alkylbenzene synthetic oils include Atmos HAB32, Atmos HAB56 (trade name, manufactured by Nippon Oil Co., Ltd.).

The synthetic oil having a polar group according to the present invention is
A compound containing a functional group having a dipole moment in the molecule. Examples of the functional group having a dipole moment include the following chemical structures.

[Chemical 2] Here, R and R'represent a residue bonded to the functional group. Examples of the synthetic oil having such a polar group are polyester oils, polyether oils and polycarbonate oils, which can dissolve at least HFC alone or in a mixture, and slide in a refrigeration cycle. A compound that maintains lubricity between members.

The polyester-based oil refers to a compound having an ester bond formed in the molecule by the reaction between a hydroxyl group and a carboxyl group. Among the polyester oils, polyester oils which are reaction products of hindered alcohols such as neopentanediol, neopentanetriol, pentaerythritol and monocarboxylic acids or dicarboxylic acids (for example, described in JP-A-2-71893). The polyester-based oil (1) is excellent in compatibility with HFC and also excellent in lubricity between sliding members in the refrigeration cycle, which is preferable.

Polyether oil is a compound having an ether bond in the molecule (for example, US Pat. No. 475).
Polyether oil described in 5316). Polyalkylene glycol, which is a reaction product of polyhydric alcohol and alkylene oxide, is preferable. Specific examples include reaction products of glycerin and propylene oxide.

Polycarbonate oil refers to a compound having a carbonic acid ester bond in the molecule (for example, JP-A-3-
Polycarbonate oils described in JP-A-149295 and JP-A-3-247695).

The refrigerator composition according to the present invention comprises (a)
Fluorine-based oils, (b) at least one hydrocarbon-based oil of naphthene-based mineral oil, paraffin-based mineral oil, and alkylbenzene-based synthetic oil, and (c) at least one of polyester-based oil, polyether-based oil, and polycarbonate-based oil It is characterized by being mixed with a synthetic oil having a polar group of.
In addition, the refrigerating machine oil of the present invention is a sulfur-based, phosphorus-based, halogen-based extreme pressure additive, or an abrasion resistance improver, an antioxidant, a heat resistance improver, a corrosion inhibitor (especially for copper) if necessary. A metal deactivator), a hydrolysis inhibitor, an antifoaming agent and the like may be included. The kinematic viscosity value (40 ° C.) of the refrigerator oil composition of the present invention is preferably 20 to 100 mm ² / s.

The compatibility of each oil component and the mixed refrigerant constituting the composition for a refrigerator according to the present invention is shown in Table 2, and the hygroscopicity of each oil component is shown in Table 3. Further, the lubricity of each oil component was measured using an abrasion tester as shown in FIG. This device
The test shaft 31 is sandwiched between V-blocks 32 and 33, the load due to the tightening of the V-block 32 is set to a constant value, the rotation of the test shaft 31 is set to a constant sliding speed condition of 290 rpm, and the refrigerator oil The amount of wear of the test shaft 31 after a lapse of a certain period of time by injecting the refrigerant while adjusting the temperature is examined. HFC134a was used as the blowing medium. The result is shown in FIG.

[Table 2]

[Table 3] The fluorine-based oil according to the present invention has a low saturated water content of 50 ppm. However, the compatibility with HFC32 and HFC134a is not good, and it does not dissolve with other refrigerating machine oils and easily separates from each other. Further, since the specific gravity is higher than other refrigerating machine oils and refrigerants in the operating temperature range, when they are present in the refrigerant compressor, they are present in the lowest layer of the coexisting refrigerant and refrigerating machine oil composition. This has the effect of particularly contributing to improving the lubricity of the sliding portion when the refrigerant compressor is started.

The hydrocarbon-based oil according to the present invention has a low saturated water content of 50 ppm. Further, although it has no compatibility with the HFC-based refrigerant, it has an effect of contributing to the improvement of the lubricity of the sliding portion. Further, the hydrocarbon-based oil has a function of dissolving the hydrocarbon-based wax which is a main depositing substance in the expansion mechanism portion such as the capillary tube. The solubility of natural paraffin wax in the refrigerant and refrigerating machine oil is shown in FIG. Thus, when a hydrocarbon-based oil is present as a refrigerating machine oil composition, it dissolves a hydrocarbon-based wax, and it is possible to prevent the deposition of depositing substances even at low temperatures, and it is possible to maintain good performance and improve durability as a refrigeration system. There is a working effect.

The synthetic oil having a polar group according to the present invention is H
It has good compatibility with FC-based refrigerants and has a function of contributing to oil return as refrigerating machine oil.

As described above, the refrigerator composition of the present invention comprises
When used together with an HFC-based refrigerant, by combining the respective components that are not completely compatible with each other, it is possible to maintain good performance and improve durability as a refrigeration system.

The blending ratio of the HFC refrigerator composition of the present invention is such that fluorine oil is 5 to 50% by weight and hydrocarbon oil is 5 to 50% by weight.
%, And 10 to 90% by weight of synthetic oil having polar groups.

Table 4 shows the compatibility of the HFC-based mixed refrigerant with the mixing ratio of the fluorine-based oil or the hydrocarbon-based oil in the HFC refrigerator composition.

[Table 4] If the fluorine-based oil or hydrocarbon-based oil exceeds 50% by weight,
Since the compatibility with the HFC refrigerant becomes poor, the oil return from the refrigeration cycle becomes insufficient. If the amount of the fluorine-based oil is less than 5% by weight, the lubricity of the sliding portion at the time of starting the refrigerant compressor is not improved, and if the amount of the hydrocarbon-based oil is less than 5% by weight, the solubility of the hydrocarbon wax is deteriorated.

FIG. 6 shows the result of measurement of the relationship between the mixing ratio of the polar group-containing synthetic oil in the HFC refrigerator composition and the wear amount ratio. If the mixing ratio of the synthetic oil having a polar group exceeds 90% by weight, the lubricity deteriorates. On the other hand, if it is less than 10% by weight, the oil return is insufficient.

As described above, when the fluorine-based oil is in the range of 5 to 50% by weight, the hydrocarbon-based oil is in the range of 5 to 50% by weight, and the synthetic oil having a polar group is in the range of 10 to 90% by weight, the refrigeration system is normally operated. Will be able to drive.

The refrigerating machine oil composition for HFCs of the present invention is particularly suitable for use in coexistence with a mixed refrigerant prepared by mixing two or more HFC refrigerants. And each oil component of the HFC refrigerating machine oil composition can be mixed corresponding to each refrigerant component of the mixed refrigerant.

For example, a fluorinated oil can reduce the amount of water in a mixed refrigerant containing HFC143a and improve the starting characteristics when starting the refrigerant compressor. Hydrocarbon-based oil can reduce the amount of water in all HFC mixed refrigerants, and can suppress the deposition of depositing substances in the expansion mechanism section such as the capillary tube. Synthetic oils with polar groups are also used in mixed refrigerants containing HFC143a.
Since it has compatibility as shown in (3), the oil can be sufficiently returned.

In the hermetic compressor of the present invention, in a system using the above HFC-based mixed refrigerant, 5 to 50% by weight of fluorine-based oil, 5 to 50% by weight of hydrocarbon-based oil and a polar group are used as refrigerating machine oil. A refrigerating machine oil composition comprising 10 to 90% by weight of a synthetic oil having The hermetic compressor according to the present invention includes a rotary compressor, a reciprocating compressor,
A vane type compressor etc. can be mentioned.

The refrigerating apparatus of the present invention comprises a refrigerant, a compression mechanism for compressing the refrigerant from a low pressure to a high pressure, a condensing mechanism for cooling the high pressure compressed refrigerant, and an expansion mechanism for expanding the condensed refrigerant. In a refrigeration system having a closed refrigeration cycle consisting of an evaporation mechanism for evaporating an expanded refrigerant, a mixed refrigerant composed of two or more HFC-based refrigerants mixed as a refrigerant, and a fluorine-based oil of 5 to 50 as a refrigeration oil. The refrigerating machine oil composition comprises 5 to 50% by weight of a hydrocarbon-based oil and 10 to 90% by weight of a synthetic oil having a polar group. Examples of the refrigerating device of the present invention include a refrigerating refrigerator and an air conditioner. In such a refrigerating apparatus, by using the mixed refrigerant and the refrigerating machine oil composition described above, it is possible to suppress the deposition of deposits in the refrigerating cycle, and obtain a refrigerating cycle that maintains high reliability and good performance. To be

[0037]

EXAMPLES Examples of the present invention will be described below. Examples 1 to 9 Demnum S-65 (manufactured by Daikin Co., Ltd.) as a fluorine-based oil, and Sniso 4GSD (manufactured by Nippon Sun Oil Co., Ltd.) of a naphthenic mineral oil as a hydrocarbon-based oil and paraffinic mineral oil. Flaole S32 (manufactured by Nikko Kyokushi Co., Ltd.) and alkylbenzene compound Atmos HAB56 (manufactured by Nippon Oil Co., Ltd., trade name) are used as synthetic oils having polar groups, and polyester-based oil Flare α56 (Nikko Koseki Co., Ltd.) is used. Made by
A commercial product) and a polyether-based oil, a polyalkylene glycol and a polycarbonate oil, are prepared respectively.
The refrigerator oil composition shown in was obtained. The mixing ratio of each is 10% by weight for fluorinated oil, 10% by weight for hydrocarbon type oil,
The synthetic oil having a polar group was 10% by weight.

[0038]

[Table 5] 500 ml of these refrigeration oil compositions and HFC32 as refrigerant
/ HFC125 (weight ratio 60/40) 600g was enclosed in the refrigerant compressor shown in Fig. 2 to form a refrigeration cycle and an air conditioner was assembled.

Each of the obtained air conditioners was operated for 2000 hours of heating at an indoor temperature of 20 ° C. and an outdoor temperature of 7 ° C. After the operation was completed, the refrigerant compressor in each example was disassembled, and the refrigerating machine oil (total acid value of the refrigerating machine oil was 0.01 mgKO
H / g), the electric wire coating material and the insulating film of the motor coil, which is a compressor part, were examined, and it was found that there was no abnormality in all of the Examples and that they were very good. Also with respect to each sliding member, particularly remarkable wear was not observed, and almost no carbon sludge was observed in the discharge valve.

After the end of the operation, nitrogen gas was introduced into the capillary tube as a means for measuring the amount of precipitates produced in the capillary tube portion, and the flow rate was measured. The result is shown in FIG. 7. In addition, the comparative example shown in FIG.
The same refrigerating cycle as in Example 1 was constructed except that only No. 6 was used and a motor component using winding oil containing hydrocarbon wax was used to assemble an air conditioner, and heating was performed under the same conditions as in Example 1. It is a figure which shows the nitrogen gas flow rate measurement result after driving for 2000 hours. As shown in FIG. 7, in Examples 1 to 9, the decrease in nitrogen gas flow rate after the operation for 2000 hours of heating was smaller than that in Comparative Example, and the refrigerator oil composition of the present invention has a sufficient effect. Was confirmed. Further, in Examples 1 to 9, even if the capillary tube in the refrigeration cycle was disassembled, almost no formation of precipitates was observed.

Examples 10 to 13 Demnum S-65 was used as a fluorine-based oil, Suniso 4GSD of a naphthene-based mineral oil was used as a hydrocarbon-based oil, and Freole α5, a polyester-based oil, was used as a synthetic oil having a polar group.
6 were prepared, and the blending ratio of each was changed to obtain the refrigerator oil composition shown in Table 6.

[0042]

[Table 6] The same refrigeration cycle as in Example 1 was constructed except that this refrigerating machine oil composition was used, and the same air conditioner as in Example 1 was assembled.

Each of the obtained air conditioners was operated for 2000 hours of heating at an indoor temperature of 20 ° C. and an outdoor temperature of 7 ° C. After the operation was completed, the refrigerant compressor in each example was disassembled, and the refrigerating machine oil (total acid value of the refrigerating machine oil was 0.01 mgKO
H / g), the electric wire coating material and the insulating film of the motor coil, which is a compressor part, were examined, and it was found that there was no abnormality in all of the Examples and that they were very good. Also with respect to each sliding member, particularly remarkable wear was not observed, and almost no carbon sludge was observed in the discharge valve. Further, when the capillary tube was disassembled after the operation was completed, almost no precipitate was found to be generated, and the nitrogen gas flow rate measurement result was the same as that in Example 1.

Example 14 and Example 15 Using the same refrigerating machine oil composition as in Example 1, HFC134a was used in Example 14 and HFC125 / H was used in Example 15 as the refrigerant.
The same refrigeration cycle as in Example 1 was constructed except that a mixed refrigerant of FC143a / HFC134a (weight ratio 44/52/4) was used, and the same air conditioner as in Example 1 was assembled. Each of the obtained air conditioners was operated at a room temperature of 20 ° C and an outdoor temperature of 7 ° C for heating for 2000 hours.

After the end of the operation, the refrigerant compressor in each of the examples was disassembled and the refrigerating machine oil (the total acid value of the refrigerating machine oil was 0.0
1 mgKOH / g), the electric wire coating material and the insulating film of the motor coil which is a compressor part were examined, and it was found that there was no abnormality in all of the Examples and that they were very good. Also with respect to each sliding member, particularly remarkable wear was not observed, and almost no carbon sludge was observed in the discharge valve. Further, when the capillary tube was disassembled after the operation was completed, almost no precipitate was found to be generated, and the nitrogen gas flow rate measurement result was the same as that in Example 1. As described above, the refrigerating machine oil composition of the present invention can be applied to any HFC refrigerant.

Example 16 A refrigerator was assembled by constructing the same refrigeration cycle as in Example 15. The obtained refrigerator was operated at a room temperature of 25 ° C. for 2000 hours continuously.

After the operation was completed, the refrigerator was disassembled, and the refrigerator oil (total acid value of the refrigerator oil was 0.01 mgKOH / g), the electric wire coating material of the motor coil, which is a compressor component, and the insulating film were examined. But turned out to be very good. With respect to each of the sliding members, no particularly noticeable wear was observed, almost no carbon sludge was observed in the discharge valve, and the nitrogen gas flow rate measurement results were the same as in Example 1. Further, when the capillary tube was disassembled after the operation was completed, almost no precipitate was found to be formed.

[0048]

The refrigerating machine oil composition used in a closed system coexisting with the HFC type refrigerant of the present invention is composed of a fluorine type oil, a hydrocarbon type oil and a synthetic oil having a polar group. It has compatibility with the system refrigerant, low hygroscopicity, good lubricity, and no precipitation of foreign matter in the refrigeration cycle.

Further, 5 to 50% by weight of fluorine-based oil, 5 to 50% by weight of hydrocarbon-based oil, and 10 to 10% of synthetic oil having a polar group are used.
By adjusting the amount to 90% by weight, the compatibility with the HFC-based refrigerant, hygroscopicity and lubricity can be further improved.

Further, the above-mentioned refrigerating machine oil composition can maintain the above-mentioned various properties well even in a system used in coexistence with a mixed refrigerant prepared by mixing two or more HFC-based refrigerants.

The hermetic compressor according to the present invention contains 5 to 50% by weight of the HFC-based mixed refrigerant and the fluorine-based oil, and 5% by weight of the hydrocarbon-based oil.
~ 50 wt% and 10-90 wt% synthetic oil with polar groups
Since the refrigerating machine oil composition consisting of the above is used, the starting characteristics of the hermetic compressor and the lubricity of the sliding parts are excellent.

The refrigerating apparatus of the present invention is a refrigerating apparatus having a closed refrigeration cycle consisting of a compression mechanism, a condensing mechanism, an expansion mechanism and an evaporating mechanism, in which two or more HFC type refrigerants are mixed as refrigerants. As a refrigerating machine oil, the mixed refrigerant is composed of 5 to 50% by weight of fluorine-based oil and 5 to 5% of hydrocarbon-based oil.
Since the synthetic oil having 50% by weight and the polar group contains 10 to 90% by weight of the refrigerating machine oil composition, each constituent part is not hindered and durability and reliability can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a refrigeration cycle for a refrigerator.

FIG. 2 is a view showing a hermetic rotary compressor in a cutaway manner.

FIG. 3 is a view showing a cross section of a wear test device.

FIG. 4 is a diagram showing a result of a wear amount test.

FIG. 5 is a diagram showing the solubility of natural paraffin wax in a refrigerant and refrigerating machine oil.

FIG. 6 is a diagram showing a measurement result of a wear amount ratio with respect to a mixing ratio of synthetic oil.

FIG. 7 is a diagram showing a measurement result of a nitrogen gas flow rate in a capillary tube.

[Explanation of symbols]

1 ... Casing, 2 ... Stator, 3 ......... Rotor, 4 ... Motor mechanism, 5 ... Compression mechanism, 6 ... Supply pipe, 7 ... Discharge pipe, 8 ... Shaft , 9 ... Bearings, 10 Cylinders, 11 Sub bearings, 12 Cranks, 13 Rollers, 14
… Blade, 15 ……… Spring, 21 ……… Capillary tube, 22 ……… Evaporator, 23 ……… Compressor, 24 ……… Cage pipe, 25 ……… Radiation pipe, 2
6 ... Clean pipe, 27 ... Refrigerator, 31 ...
… Test shafts, 32, 33 ……… V-blocks.

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Claims (5)

[Claims] 1. A refrigerating machine oil composition used together with a hydrofluorocarbon-based refrigerant, wherein the refrigerating machine oil composition comprises a fluorine-based oil, a hydrocarbon-based oil and a synthetic oil having a polar group. A refrigerating machine oil composition for HFCs. 2. The refrigerating machine oil composition for HFCs according to claim 1, wherein the fluorine-based oil is 5 to 50% by weight, the hydrocarbon-based oil is 5 to 50% by weight, and the polar group-containing synthetic oil is 10 to 50% by weight. A refrigerating machine oil composition for HFCs, wherein the refrigerating machine oil composition comprises from about 90 wt%. 3. The refrigerating machine oil composition for HFCs according to claim 2, wherein the hydrofluorocarbon-based refrigerant is 2
A refrigerating machine oil composition for HFCs, which is a mixed refrigerant obtained by mixing the above hydrofluorocarbon-based refrigerants. 4. A mixed refrigerant in which a compression mechanism is housed in a closed container and two or more hydrofluorocarbon-based refrigerants are mixed as a refrigerant, and 5 to 50% by weight of a fluorine-based oil as a refrigerating machine oil and carbonized. A hermetic compressor characterized by using a refrigerating machine oil composition comprising 5 to 50% by weight of a hydrogen-based oil and 10 to 90% by weight of a synthetic oil having a polar group. 5. A refrigerant, a compression mechanism for compressing the refrigerant to a pressure higher than a low pressure, a condensing mechanism for cooling the refrigerant compressed to a high pressure, an expansion mechanism for expanding the condensed refrigerant, and the expansion mechanism. In a refrigerating apparatus having a closed refrigeration cycle consisting of an evaporation mechanism for evaporating a refrigerant, a mixed refrigerant formed by mixing two or more hydrofluorocarbon-based refrigerants as the refrigerant, and a fluorine-based oil as a refrigerating machine oil of 5 to 50 A refrigeration system comprising a refrigerating machine oil composition comprising 5 to 50% by weight of a hydrocarbon-based oil and 10 to 90% by weight of a synthetic oil having a polar group.